JP2519580Y2 - Turntable structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a turntable suitable for a magneto-optical disk or the like.

(Prior Art) FIG. 4 is a cross-sectional view of a conventional spindle motor equipped with a turntable. The spindle motor 100 rotatably supports a motor shaft 104 in a motor housing 101 via bearings 102 and 103. A rotary yoke 106 is attached via a bush 105 press-fitted to one end (lower end) of 104, a magnet 107 is fixed to the rotary yoke 106, and a core 108 and a coil 10 are opposed to the magnet 107.
9 is fixed to the motor housing 101.

On the other hand, the turntable 120 has a ring magnet 123 fixed to the annular groove 121 via a back yoke 122.

FIG. 5 is an operation diagram of FIG. 4, in which the magneto-optical disk 131 having the disk clamp yoke 130 in the center is shown in FIG.
Set to 20. The magneto-optical disk 131 is pressed and fixed to the turntable by the disk clamp yoke 130 being magnetically attracted to the ring magnet 123.

(Problems to be solved by the invention) By the way, the ring magnet 123 is bonded to the back yoke 122 with the adhesive 132 shown in FIG.
122 is bonded to the turntable 120 with an adhesive 133.

Since the thicknesses of the back yoke 122 and the ring magnet 123 vary within the range of processing accuracy, and it is difficult to make the thicknesses of the adhesives 132 and 133 uniform, as shown in FIG.
When the adhesive 133, the back yoke 122, the adhesive 132, and the ring magnet 123 are stacked in this order on 0, the ring magnet 123
The level of the upper surface 123a of the product varies from product to product.

If the gap between the upper surface 123a of the ring magnet 123 and the lower surface 130a of the disc clamp yoke 130 is Gd, there is a physical rule that the clamping force of the ring magnet 123 on the magneto-optical disc 131 is inversely proportional to the square of Gd.

FIG. 6 is a graph showing the relationship between the gap Gd and the clamping force in FIG. 5, and when the gap Gd in FIG. 5 is measured, the variation is about ± 0.15 mm, and the corresponding variation in the clamping force. Is about ± 3 N (Newton).

If the clamping force is small, the magneto-optical disk at startup
131 may slip and damage the receiving surface of the turntable 120 or the lower surface of the magneto-optical disk 131.

On the other hand, when the clamping force is large, the magneto-optical disk 13
A great amount of force is required to pull 1 from the turntable 120.

Further, when the adhesives 132 and 133 are deteriorated during high temperature and high humidity or when high temperature and low temperature are repeated, and the ring magnet 123 repeatedly attracts the disc clamp yoke 130, the ring magnet 123 and the back yoke 122 may come off.

Therefore, an object of the present invention is to improve the mounting structure of the ring magnet and the back yoke.

(Means and Actions for Solving the Problem) In order to achieve the above object, the present invention provides a turntable supported by a spindle motor with a large-diameter recess, in which the adhesive accommodating portion and the inside thereof are provided. An annular groove is continuously provided, and a back yoke having an L-shaped cross section is fitted into the annular groove so that the upright piece faces the adhesive accommodating portion, and a ring magnet is accommodated in the annular groove via the back yoke. A large chamfered portion is provided above the outer peripheral surface of the ring magnet, and the adhesive agent accommodating portion and the chamfered portion are filled with an adhesive agent for connecting the ring magnet and the turntable.

The fitting work may be performed until the distance between the upper surface of the turntable and the upper surface of the ring magnet reaches a predetermined value.
Further, the upper portion of the upright piece of the back yoke, the ring magnet and the turntable are fixed to each other with an adhesive.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a spindle motor having a turntable according to the present invention, and the spindle motor 100 is the same as that described in the section of the related art, so the description thereof will be omitted.

The turntable 1 has a large-diameter first concave portion 2 and an annular groove 3 corresponding to a small-diameter second concave portion formed from the upper surface toward the lower surface. Further, in the vicinity of the intersection of the first concave portion 2 and the annular groove 3. Has an adhesive accommodating portion 4 including a reverse taper surface 4a narrowing upward and a horizontal step portion 4b.

The back yoke 6 is formed in an L-shaped cross section, and the outer peripheral surface diameter D1 (see FIG. 2) of the standing piece 7 is the outer peripheral surface of the annular groove 3.
The size is slightly larger than the diameter D2 of 3a.

The ring magnet 9 has a chamfered portion 10 on the outer edge of the upper surface 9a.

Assembly of the turntable structure having the above configuration will be described below.

FIG. 2 is an assembly explanatory view of the present invention, which is a back yoke 6.
Then, the ring magnet 9 is bonded with the adhesive 11 (arrow).

An adhesive 12 is applied to the bottom of the annular groove 3 to an appropriate thickness, and the back yoke 6 is press-fitted (arrow). At this time, the gap Ge (FIG. 1) from the upper surface 1a of the turntable 1 to the upper surface 9a of the ring magnet 9 is press-fitted to a predetermined value.
Therefore, the thickness of the adhesive 12 changes to serve as an adjustment allowance.

The adhesive 13 is filled in the chamfered portion 10 of the adhesive accommodating portion 4 and the ring magnet 9 and hardened.

FIG. 3 is an assembled view of the turntable structure of the present invention, in which the gap Ge between the upper surface 9a of the ring magnet 9 and the upper surface 1a of the turntable 1 is set to a desired value, and the back yoke 6 is the outer periphery of the annular groove 3. Fitting and adhesion to surface 3a (adhesive 13)
And is firmly fixed to the turntable 1.

The ring magnet 9 is adhered (adhesive 11) to the back yoke 6 and is fixed to the reverse taper surface 4a by an adhesive 13.

As shown in the figure, the gap Gf between the lower surface of the disc clamp yoke 14 and the upper surface 9a of the magnet 9 is in a desired range with high accuracy, and the clamping force is always a constant value.

(Effect of the Invention) As described above, the present invention configures the turntable so that the upper surface of the ring magnet has a predetermined size from the upper surface of the turntable, so the clamping force is stable. Since the component error does not directly affect the assembling dimension, it is not necessary to make the thickness dimension of the ring magnet and the back yoke so severe, so that the processing cost can be reduced.

Therefore, according to the present invention, the sticking force of the magnet to the turntable can be greatly increased by simply changing the shapes of the components.

Further, according to the present invention, by filling the adhesive containing portion provided in the recess of the turntable and the chamfered portion provided at the upper portion of the outer peripheral surface of the ring magnet with the adhesive for connecting the ring magnet and the turntable. The stress due to heat shock is dispersed in the thickness of the adhesive even during high temperature and high humidity or when high temperature and low temperature are repeated, and the adhesive is less likely to be broken, and the ring magnet and the back yoke can be firmly fixed to the turntable. Then, the adhesion state after adhesion can be easily confirmed by visual inspection, and the reliability of the turntable can be greatly improved.

[Brief description of drawings]

1 is a sectional view of a spindle motor having a turntable according to the present invention, FIG. 2 is an assembly explanatory diagram of the present invention, and FIG.
FIG. 4 is an assembled view of a turntable structure of the present invention, FIG. 4 is a sectional view of a spindle motor having a conventional turntable, FIG. 5 is an operation view of FIG. 4, and FIG. 6 is a gap in FIG. 6 is a graph showing the relationship between Gd and clamping force. 1 ... Turntable, 2 ... Recess, 3 ... Annular groove, 4
…… Adhesive storage, 6 …… Back yoke, 7 …… Standing piece, 9 …… Ring magnet, 10 …… Chamfer, 13 ……
Adhesive, 100 ... Spindle motor.

Claims (1)

(57) [Scope of utility model registration request] 1. A turntable pivotally supported by a spindle motor is provided with a large-diameter recess, and an adhesive accommodating portion and an annular groove inside thereof are continuously provided in the concave, and the annular groove has an L-shaped cross section. -Shaped back yoke is fitted such that its upright piece faces the adhesive housing portion, and a ring magnet is further housed in the annular groove via the back yoke, and a large chamfered portion is provided above the outer peripheral surface of the ring magnet. A turntable structure, characterized in that an adhesive containing portion and a chamfered portion are filled with an adhesive for connecting a ring magnet and a turntable.